This invention relates to latches for vehicle doors, particularly for light passenger and goods vehicles.
Powered locking and powered latching of doors is becoming more favored, both as part of central locking systems and to enable more effective weathersealing of doors and greater freedom in styling and design. There are also advantages in providing for power actuated unlatching of doors in terms of dispensing with much of the mechanical linkage and components needed for conventional manual inside and outside door handles and in providing unitary lock and latch modules of standard form which can be speedily installed in doors of a wide range of vehicle models and types without special adaptation.
An example of the provision of power closing is described and claimed in our co-pending application, Publication Number GB 2328242 dated Feb. 17, 1999, and the present invention may conveniently be combined with that construction if desired.
Examples of the provision of power actuated unlatching are described and claimed in our co-pending patent applications, Publication Numbers GB 2329416 dated Mar. 24, 1999 and GB 2339593 dated Feb. 2, 2000.
The object of the invention is to provide improvements in vehicle door latches having a power unlatching facility in an economical, effective and reliable form, and providing enhanced safety in their use and operation.
A vehicle door latch assembly includes a latch operatively co-acting with a striker as the door nears a closed position. A latching pawl self-engages with the latch and holds the latch in a latched condition, retaining the door. An unlatching mechanism is selectively operable to disengage said latching pawl for opening the door and includes a pawl lifter movable from a position of rest to carry the latching pawl out of engagement with the latch and a manually operable release member operatively linked to a handle of the door to engage and displace the pawl lifter from the position of rest. The unlatching mechanism also includes a power output member movable to engage and displace the pawl lifter from the position of rest, an input member power actuated between a first position and a second position which is releaseably drive connected to the output member to cause shifting of the output member as the input member moves to the second position, and an overriding element carrying the input member and the outlet member into and out of drive connection and being resiliently urged to a clutch disconnecting condition. The release member includes a formation co-acting with the overriding element to displace the overriding element to a clutch connecting condition. Power actuation of the input member occurs after shifting of the release member
According to the invention there is provided a vehicle door latch assembly as defined by Claim 1 of the appended claims.